منابع مشابه
Extension of Hereditary Classes with Substitutions Extension of Hereditary Classes with Substitutions
Let G and H be graphs. A substitution of H in G instead of a vertex v 2 V (G) is the graph G(v ! H), which consists of disjoint union of H and G ? v with the additional edge-set fxy : x 2 V (H); y 2 N G (v)g. For a hereditary class of graphs P, the substitutional closure of P is deened as the class P consisting of all graphs which can be obtained from graphs in P by repeated substitutions. Let ...
متن کاملRole colouring graphs in hereditary classes
We study the computational complexity of computing role colourings of graphs in hereditary classes. We are interested in describing the family of hereditary classes on which a role colouring with k colours can be computed in polynomial time. In particular, we wish to describe the boundary between the “hard” and “easy” classes. The notion of a boundary class has been introduced by Alekseev in or...
متن کاملOn growth rates of hereditary permutation classes
A class of permutations is called hereditary if implies where the relation is the natural containment of permutations Let n be the set of all permutations of n belonging to We investigate the counting functions n j nj of hereditary classes Our main result says that if j nj n for at least one n then there is a unique k such that Fn k j nj Fn k n c holds for all n with a constant c Here Fn k are ...
متن کاملOn Hereditary Helly Classes of Graphs
In graph theory, the Helly property has been applied to families of sets, such as cliques, disks, bicliques, and neighbourhoods, leading to the classes of clique-Helly, disk-Helly, biclique-Helly, neighbourhood-Helly graphs, respectively. A natural question is to determine for which graphs the corresponding Helly property holds, for every induced subgraph. This leads to the corresponding classe...
متن کاملVertex elimination orderings for hereditary graph classes
We provide a general method to prove the existence and compute efficiently elimination orderings in graphs. Our method relies on several tools that were known before, but that were not put together so far: the algorithm LexBFS due to Rose, Tarjan and Lueker, one of its properties discovered by Berry and Bordat, and a local decomposition property of graphs discovered by Maffray, Trotignon and Vu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Glasgow Mathematical Journal
سال: 1970
ISSN: 0017-0895,1469-509X
DOI: 10.1017/s0017089500000781